Floating tool holder

ABSTRACT

In a floating tool holder having a shank, a body driven thereby and an adapter assembly removably secured to and driven by said body, the improvement which includes a float disc interposed between said body and adapter assembly. A series of axial apertures extend through the disc and transverse slots are formed in opposing end faces thereof. End thrust separator balls are nested in the axial apertures for engagement with said body and adapter assembly to permit copensating lateral translation of the adapter assembly relative to said body. Drive balls are nested in the float transverse slots to project into corresponding opposed transverse slots in the corresponding inner ends of said body and adapter assembly.

United States Patent 1 [111 3,740,063 Smith June 19, 1973 FLOATING TOOLHOLDER Primary Examiner-Gil Weidenfeld [76] inventor: Theodore M. Smith,14750 Puritan Atmmey cunen Settle Sloman & Cantor Avenue, Detroit, Mich.48227 57 ABSTRACT [22] Filed: Oct. 15, 1971 Appl. No.: 189,654

[52] US. Cl. 279/16, 408/16 [51] Int. Cl. B23c 31/04, B23b 49/00 [58]Field of Search 279/16, 17, 18, l L, 279/1 J; 10/89 F, 129, 141 H;408/16, 11

[56] References Cited UNITED STATES PATENTS 3,454,283 7/1969 Benjamin etal 279/16 2,007,897 7/1935 Skeel 1,907,447 5/1933 Schiltz 1,241,1759/1917 Watts 82/].3

In a floating tool holder having a shank, a body driven thereby and anadapter assembly removably secured to and driven by said body, theimprovement which in cludes a float disc interposed between said bodyand adapter assembly. A series of axial apertures extend through thedisc and transverse slots are formed in opposing end faces thereof. Endthrust separator balls are nested in the axial apertures for engagementwith said body and adapter assembly to permit copensating lateraltranslation of the adapter assembly relative to said body. Drive ballsare nested in the float transverse slots to project into correspondingopposed transverse slots in the corresponding inner ends of said bodyand adapter assembly.

8 Claims, 5 Drawing Figures seem u a PATENTED JUN 1 9 i973 SIEEIIBFFLOATING TOOL HOLDER BACKGROUND OF THE INVENTION Heretofore, in the useof tool holders, these have normally included a power rotated andlongitudinally fed shank which axially projects into the tool holderbody driven thereby and within the free end of the body, there isremovably positioned an adapter assembly of various types adapted toremovably receive and secure and rotatively drive a tool holdingadapter. In constructions of this type, there is often some misalignmentbetween the longitudinal axis of the shank and body and the longitudinalaxis of the hole being bored or tapped with the result that certaintransverse pressures are applied to the adapter assembly, ultimatelycausing malfunction of the tool holder.

BRIEF DESCRIPTION OF THE INVENTION It is an object of the presentinvention to provide an improved floating tool holder wherein a means isprovided to removably mount adapter assembly for rotation with said bodybut at the same time free for lateral translation on axes parallel tothe body axis to automatically compensate for misalignment between theaxis of the body and the axis of the aperture being machined, tapped,drilled or reamed.

It is another object to provide an improved mounting for the adapterassembly with respect to the power rotated body wherein there isprovided a floating relationship in the nature of an end thrust floatmechanism which is interposed between the body and the adapter assembly.This is to permit relative lateral translation of the adapter assemblywith respect to the body and which at the same time, retain drivingengagement therebetween.

These and other objects will be seen from the following specificationand claims in conjunction with the appended drawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary partly brokenaway longitudinal section of the present floating tool holder with oneform of adapter assembly; namely, an Acme adapte assembly.

FIG. 2 is a perspective view of an alternately usable single tap holdingadapter assembly. 7

FIG. 3 is a perspective view of an alternately usable quick changeadapter assembly adapted to receive a range of tap sizes andcorresponding adapters.

FIG. 4 is a perspective view of an" alternately usable morse taperadapter assembly.

FIG. 5 is a bracketed perspective view of the float disc shown in FIG. Iwith the end thrust and drive balls shown in exploded relation.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. I there is shownpartly broken away a longitudinal section of the present floating toolholder generally indicated at and including power rotated andlongitudinal feedable shank 11 adapted for mounting and securing withina power driven machine tool spindle of conventional construction, notshown.

The present floating tool holder also includes an elongated axiallydisposed body 12 which receives one end of said shank and is rotativelydriven and longitudinally fed thereby. One form of adapter assembly 13known as an Acme adapter assembly, is axially aligned normally with body12 and is suitably secured thereto by the float cap assembly wherein theadapter assembly may be removably interlocked with the body in rotativedriven relation.

The present power rotated andlongitudinally feedable shank includes athreaded end portion 15 by which it is projected into and secured to apower rotated and longitudinally fed machine spindle. Its opposite endterminates in a transverse end face 16 and projecting thereinto theaxial bore 17.

Intermediate the ends of the shank is an annular re cess 18 adapted toreceive a series of spaced balls 19. The source ring generally indicatedat 20 is in the nature of a metallic ring which has been impregnatedwith a radioactive material and is mounted within a correspondingannular exterior recess in a portion of the shank adjacent its threadedportion.

Formed within the elongated axially arranged body 12 within whichprojects one end of said shank, are a plurality of elongated slots 21which are inclined with respect to longitudinal axis of the body and areadapted to receive projecting portions of the balls 19 carried by saidshank. The forward end 22 of said body is of reduced exterior diameterand is threaded at 23 and includes an axial counterbore 24. The bore ofsaid body terminates in the radial inner end :face 25 which is normallyspaced from the end face 16 of said shank.

In normal operation on initial rotation of shank 11, balls 19 movein'the inclined slots 21 in body 12 causing an inward movement of theshank relative to said body. This moves the source ring so as to beprotectively enclosed by the recessed portion 32' in said body, FIG. 1.In the event of a malfunction, the above relative movement is prevented,causing the ring 20 to activate an electronic tool failure detectionsystem, such as shown in applicants US. Pat. No. 3,566,719 of May 2,I971.

Centering cup 26 is snugly projected through bore 24 of said body andsecured thereto and projects forwardly thereof as shown in FIG. 1.Torsion compression spring 27 also referred to as a cocking spring isnested within bore 17 of the shank and projects within the main bore ofthe body and bears against its inner radial wall 25 with cup shaped seat29 interposed, and is secured to mend to the body by the elongated screw30 threaded into the bore of centering cup 26. The opposite end ofspring 27 is axially secured to the shank by anchoring screw 28.

Across the outer end face of body portion 22 there is provided a pair ofaligned transverse slots 31.

Elongated exteriorly knurled float cap 32 has an internal bore 33terminating in a retaining shoulder 34 at one end and at its oppositeend is interiorly threaded at 35 for securing registry over the threadedend 22 of said body.

A pair of semicircular adapter retaining split rings 36 bear against theshoulder 34 within said float cap and extend radially and loosely intothe exterior annular recess 37 on the inner end portion 38 of adapterassembly 13. The inner surfaces of the split rings extend only partlydown into the adapter assembly recess 37 so that said adapter assemblyis capable of lateral translation for rotation upon axes which areparallel to the body axis.

The float disc 39, shown in detail in FIG. 5, loosely receives thecentering cup 26 and is interposed between the registering adjacent endsof the body and adapter assembly.

Across the inner end face of the adapter assembly there is provided apair of transverse radial slots 39' such as clearly shown in the variousadapter assemblies of FIGS. 2, 3 and 4.

The function of the float disc 39 is to provide a means of transmittingrotational power drive between the body 12 and the adapter assembly 13but at the same time permit the loosely mounted adapter assembly limitedlateral translation movements upon axes which remain parallel to thebody axis.

For this purpose said float disc, FIG. 5, is of cylindrical form with acentral bore 40 and has formed therethrough a series of axial apertures41 which are equidistantly spaced from the disc axisv Aligned transverserecesses 42 are formed across one end face of float disc 39, and asecond pair of transverse aligned recesses 43 are formed across itsopposite face and preferably arranged at right angles to the firsttransverse recesses 42.

Corresponding metal balls 44 are nested within the respective axialapertures 41 with outer portions of the balls projecting longitudinallyoutward of the respective apertures for cooperative end thrust bearingengagement with corresponding end face portions of the respective bodyand adapter assembly.

The additional pairs of drive balls 45 are nested within the floatrecesses 42 with portions of said balls cooperatively nesting within thecorresponding transverse end slots 31 of said body, as shown in FIG. 1.

Within the oppositely arranged disc recesses 43 are the additionaltransversely arranged pairs of balls 46 which project longitudinally forcooperative'nesting and driving engagement within the correspondingtransverse slots 39 of the respective adapter assembly 13.

Thus, the float disc 39 with its respective end thrust balls 44 anddrive balls 45 and 46 provide a means of transmitting rotative drivemotion from the body to the adapter assembly and at the same timeprovide for transverse automatic adjustments of the adapter assembly soas to move into axes of rotation which are laterally displaced from andparallel to the body axis. This compensates for any misalignment betweensaid axis and the axis of the hole being, tapped or otherwise machined.

Cylindrical float spacer 47 is nested within float cap 32 and one endretainingly bears against the split retaining rings 36 and at itsopposite end bears against the corresponding end face of the body.

In the illustration, FIG. 1, the end portion 38 of the adapter assemblywhich projects into float cap 32 is spaced radially inward from floatspacer 47 so that the adapter assembly is thus capable of and free tomake transverse lateral adjustments for rotation in planes parallel tothe body axis.

With the adapter assembly 13 removed from the body, the float cap 32 isnormally retracted from the position shown to permit the assembly of theadapter retaining split rings 36 and thereafter the float spacer 47.Thereafter the float disc is nested within the float cap and the latteris advanced and its free end is threaded over the corresponding threadedend 22 of the body, with the float disc 39 loosely receiving thecentering cup 26.

The adapter assembly 13 in FIG. 1 is an Acme adapter assembly adapted toremovably receive and have interlocked therewith a suitable adaptermounting a tap or other tool. In this construction, at the forward endthereof there are a series of transverse apertures 52 adapted to receivethe balls 51 which in the position of the cam surface 50 of the releasesleeve 48 biased outwardly by spring 49 is adapted to lock a particulartool adapter into position with its conventional key nested within thecorresponding key slot formed within the adapter assmebly. To retract orwithdraw the adapter for the tool it is necessary to manually retractthe ball retaining sleeve 48 against the action of spring 49 so that theinclined surface 50 is retracted and the balls 51 can move laterallyoutward sufficiently to disengage the particular adapter. Thisconstruction forms no part of the present invention and further detailthereof is omitted.

Instead of the adapter assembly 13 in FIG. 1, this may be replaced bythe adapter assembly 53 adapted to mount within its bore 54 and retaintherein a single tap, not shown.

This adapter assembly also has a corresponding annular recess 37corresponding to the adapter assembly 13, FIG. 1, adapted to receive thecorresponding adapter retaining split rings 36 in the same manner asdescribed with respect to FIG. 1; and wherein the balls 46 mounted onthe float disc drivingly nest within the corresponding transverse slots39 in the inner end face of said adapter assembly.

In FIG. 3 there is generally indicated quick change adapter assembly 55which is adapted to removably mount a series of adapters for a range oftap sizes. Annular retaining slot 37 is the same as is also the end facetransverse slots 39'.

Another type of adapter assembly is designated at 56 and has a taperedbore at 57 adapted to receive a range of Morse taper type tools. Hereagain, retaining recess 37 is the same and corresponding transverse endface slots 39' are the same for cooperatively receiving correspondingdriven balls 46 mounted upon the inner face of float disc 39.

Thus, by the present construction a variety of adapter assemblies may beinterlockingly mounted upon and with respect to the body by means of thefloat cap assembly 14 and utilizing the present float disc 39.

By this construction regardless of the nature of the adapter assemblyemployed, said adapter assembly is securely mounted in normal axialalignment with respect to the body axis, but by virtue of theconstruction of the float disc and the arrangement for holding theadapter assembly in position utilizing the adapter retaining rings 36 iscapable for such lateral translation so that the adapter assembly canrotate on axes which are displaced from and parallel to the body axis tothus compensate for misalignment between the bore of the workpiece beingmachined and the body. axis.

The centering cup 26 has a longitudinal bore which at one end receivesthe centering spring adjusting screw 30, and at its other end 58 isopen. Axially disposed at the inner end of the adapter assembly is anoppositely arranged conical seat 59 with a suitable end thrust ball 60or centering ball interposed and engaging seat 59. The centering spring61 is nested within the centering cup bore and is interposed between theadjusting screw 30 and ball 60 to normally bias the ball against coneshaped seat 59.

By this construction, in the event that there are transverse forces dueto nonalignment of the bore of the workpiece being machined or tappedand the body axis, any lateral translation of the adapter assembly willin effect cause a riding up of portions of the ball upon and withrespect to the adapter assembly conical seat 59. Accordingly, when theshank has been retracted and pressure relieved, the adapter assemblywill automatically realign to the position shown in FIG. I and thus isself aligning.

Having described my invention reference should now be had to thefollowing claims.

I claim:

1. In a floating tool holder having a power rotated and longitudinallyfed shank, a drive body coaxially mounted over one end of and drivinglyengaged by and adapted for relative longitudinal movement with respectto said shank, and an adapter assembly axially aligned with andremovably and drivingly connected to said body for selectively mountingone of a plurality of tool carrying adapters; the improvement comprisingan apertured float cap at one end secured to-said body and at its otherend removably receiving said adapter assembly and securing same againstrelative longitudinal movement; the respective inner ends of said bodyand adapter assembly being transversely sloteted; a float disc looselynested within said cap having a series of axial apertures therethroughand upon its outer faces transverse right angularly related slots;separator end thrust balls movably positioned within said axialapertures and projecting outwardly of its outer faces for cooperativeengagement with said body and adapter assembly; and additional ballsnested in said float transverse slots and projecting axially thereof andrespectively into the corresponding end transverse slots of said bodyand adapter assembly, for driving rotation of said adapter assembly,said float disc and adapter assembly being adapted for compensatinglateral translation for rotation on axes parallel to said float axis.

2. In the floating tool holder of claim 1, the drive engagement betweensaid shank and body including an annular groove in the shank mounting aplurality of spaced balls projecting therefrom, there being a series ofinwardly opening slots in said body inclined to the body axiscooperatively receiving said balls to provide an initial longitudinalcompensating movement of said shank with respect to said body andsuccessive rotation thereof.

3. In the floating tool holder of claim 2, a torsion cocking springaxially interposed between said shank and body compressed and placedunder torsion on initial relative longitudinal movement of said shankand body whereby upon release of said feed pressure and drive to saidshank and retraction thereof, there will be an automatic relativelongitudinal movement in the opposite direction between said body andshank.

4. In the floating tool holder of claim 2, a radioactive impregnatedring on said shank normally spaced from said body and adapted uponnormal relative longitudinal movement of said shank and body to moveinto a shielded position within an undercut annular groove in said body.

5. In the floating tool holder of claim 1, the securing of said adapterassembly to said float cap including an annular groove in the inner endportion of said adapter assembly projecting into said float cap, and asplit ring nested and retained in said cap and radially projectingloosely into said annular groove, so that said adapter assembly is freefor limited lateral translation.

6. In the floating tool holder of claim 5, a float spacer in said floatcap loosely receiving and enclosing said float disc and adjacent endportion of said adapter assembly and snugly interposed between saidsplit rin and body.

7. In the floating tool holder of claim 1, the balls in said float discaxial apertures being equal distances from the float axis, there beingtwo pair of radially extending aligned balls on each end of said floatdisc within its radial slots.

8. In the floating tool holder of claim 1, an elongated centering cupaxially secured to and projected through said body at its inner end andloosely through said float disc and having a bore open at one end;

an oppositely arranged coaxially aligned cone shaped seat in acorresponding end portion of said adapter assembly; a centering ballnested in said seat; and adjustable spring means in said cup borebearing against said ball, whereby the adapter assembly and body arenormally biased into axial alignment; said ball on relative lateraltranslation of said adapter assembly riding the inclined surface of saidadapter assembly seat, whereby upon release of drive and feed andretraction of said shank and body, said adapter assembly automaticallyrealigns with said body.

UNITED STATES PATENT OFFICE CERTIFICATE OF CURRECTION Patent No.3,740,063 Dated June 19,, 1973 Inventor(s) Theodore mith It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

On the cover sheet insert I73] Assignee: Lucille G.

Smith and Theodore M. Smith, Trustees of the Theodore M. Smith Trust,Detroit, Mich.

Signed and sealed this 26th day of February 1974.

(SEAL) Attest:

EDWARD.M.FLET(;HER,JR. C MARSHALL DANN' I Attestlng Offlcer Commissionerof Patents FORM Podoso no'ss) USCOMM-DC soars-pen ".5. GOVERNMENTPRINTING OFFICE 1 0"IC'Ql.

1. In a floating tool holder having a power rotated and longitudinallyfed shank, a drive body coaxially mounted over one end of and drivinglyengaged by and adapted for relative longitudinal movement with respectto said shank, and an adapter assembly axially aligned with andremovably and drivingly connected to said body for selectively mountingone of a plurality of tool carrying adapters; the improvement comprisingan apertured float cap at one end secured to said body and at its otherend removably receiving said adapter assembly and securing same againstrelative longitudinal movement; the respective inner ends of said bodyand adapter assembly being transversely sloteted; a float disc looselynested within said cap having a series of axial apertures therethroughand upon its outer faces transverse right angularly related slots;separator end thrust balls movably positioned within said axialapertures and projecting outwardly of its outer faces for cooperativeengagement with said body and adapter assembly; and additional ballsnested in said float transverse slots and projecting axially thereof andrespectively into the corresponding end transverse slots of said bodyand adapter assembly, for driving rotation of said adapter assembly,said float disc and adapter assembly being adapted for compensatinglateral translation for rotation on axes parallel to said float axis. 2.In the floating tool holder of claim 1, the drive engagement betweensaid shank and body including an annular groove in the shank mounting aplurality of spaced balls projecting therefrom, there being a series ofinwardly opening slots in said body inclined to the body axiscooperatively receiving said balls to provide an initial longitudinalcompensating movement of said shank with respect to said body andsuccessive rotation thereof.
 3. In the floating tool holder of claim 2,a torsion cocking spring axially interposed between said shank and bodycompressed and placed under torsion on initial relative longitudinalmovement of said shank and body whereby upon release of said feedpressure and drive to said shank and retraction thereof, there will bean automatic relative longitudinal movement in the opposite directionbetween said body and shank.
 4. In the floating tool holder of claim 2,a radioactive impregnated ring on said shank normally spaced from saidbody and adapted upon normal relative longitudinal movement of saidshank and body to move into a shielded position within an undercutannular groove in said body.
 5. In the floating tool holder of claim 1,the securing of said adapter assembly to said float cap including anannular groove in the inner end portion of said adapter assemblyprojecting into said float cap, and a split ring nested and retained insaid cap and radially projecting loosely into said annular groove, sothat said adapter assembly is free for limited lateral translation. 6.In the floating tool holder of claim 5, a float spacer in said float caploosely receiving and enclosing said float disc and adjacent end portionof said adapter assembly and snugly interposed between said split ringand body.
 7. In the floating tool holder of claim 1, the balls in saidfloat disc axial apertures being equal distances from the float axis,there being two pair of radially extending aligned balls on each end ofsaid float disc within its radial slots.
 8. In the floating tool holderof claim 1, an elongated centering cup axially secured to and projectedthrough said body at its inner end and loosely through said float discand having a bore open at one end; an oppositely arranged coaxiallyaligned cone shaped seat in a corresponding end portion of said adapterassembly; a centering ball nested in said seat; and adjustable springmeans in said cup bore bearing against said ball, whereby the adapterassembly and body are normally biased into axial alignment; said ball onrelative lateral translation of said adapter assembly riding theinclined surface of said adapter assembly seat, whereby upon release ofdrive and feed and retraction of said shank and body, said adapterassembly automatically realigns with said body.